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Origins, insertions, innervation and functions of the extensor digitorum longus.
Hey there! It’s Matt from Kenhub! And in this tutorial, we will discuss the function and anatomy of the extensor digitorum longus.
The extensor digitorum longus or Musculus extensor digitorum longus is one of the anterior muscles of the lower leg.
These anterior muscles are a group of extensors. They lie within the anterior compartment located at the ventrolateral region of the lower leg where they form its surface structure.
Their tendons are particularly prominent on the dorsum of the foot. They include the tibialis anterior, the extensor hallucis longus, and the extensor digitorum longus.
The extensor digitorum longus muscle has three points of origin. It originates at the lateral tibial condyle, the ventral side of the fibula, and the interosseous membrane, and merges into a tendon above the superior extensor retinaculum.
Below the inferior extensor retinaculum, it divides into four tendons inserting at the dorsal aponeurosis and the bases of the distal and middle phalanges of the second through fifth toes.
About 90% of people have an additional fifth tendon running towards the lateral foot edge and inserting at the fifth metatarsal bone.
All anterior muscles are innervated by the deep fibular nerve.
The main task of the anterior muscles of the lower leg is the dorsal extension of the upper ankle joint.
In addition, both the extensor digitorum longus and extensor hallucis longus muscles are responsible for the lifting of the toes, the extension of the first, middle, and end joints.
Due to the course of the tendons, the anterior muscles also contribute to the movement of the lower ankle joint. And in this function, the extensor digitorum longus muscle provides a powerful eversion known as pronation.